Reading spreadsheet with values in column without header fails

If spreadsheet does have a value in column without header, like this:

| header1 | header2 |     |
|---------|---------|-----|
| foo     | bar     |     |
| bar     | baz     | ban |


The parsing fail in `SpreadsheetsReader::readById()` in the `array_combine()` call, as the arrays have different number of items.